Insecticidal activity of the pyrethrins and related compounds: III.—Penetration of pyrethroid insecticides into mustard beetles (Phaedon cochleariae)

Substituted benzyl chrysanthemates are lost from the surface of Phaedon cochleariae Fab. at rates correlated with their toxicities to this insect, less toxic compounds in general being lost faster. The forms of the penetration curves are explained by a model system in which movement into the insect is eventually balanced by detoxification, and relative detoxification rates for the members of the series of compounds are deduced from this model. Such values assist interpretation of relations between structure and activity by indicating to what extent susceptibility to detoxification limits the potency of the less toxic compounds.